要做一个关于分页写法的专题，这是今天的第一讲，自制分页，可能有些代码需要优化，希望大家给出一些中肯的建议
前台使用的repeater绑定的数据：
<form id="form1" runat="server"> <div> <ul style="list-style: none"> <asp:Repeater ID="Repeater1" runat="server"> <ItemTemplate> <li><%#Eval("Title") %></li> </ItemTemplate> </asp:Repeater> </ul> </div> <div id="pagerwrapper"> <table id="pager" cellspacing="0"> <tbody> <tr> <td colspan="5"> <%=RePager %> 跳转至：<asp:TextBox ID="TxtPager" runat="server"></asp:TextBox>页 <asp:Button ID="BtnOk" runat="server" Text="确定" OnClick="BtnOk_Click" /> </td> </tr> </tbody> </table> </div> </form>
后台代码写法如下：注释已标明：
using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; using System.Data; using System.Data.SqlClient; using System.Configuration; namespace WebApplication1 { public partial class WebForm2 : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { if(!IsPostBack) { GetDate(); } //这样写可以避免第一次加载之后再次加载不显示的问题 GetPager(); } string ConStr = ConfigurationManager.ConnectionStrings["Connection"].ToString(); public string pager = string.Empty; public string RePager = string.Empty; int startcount = 0; int endcount = 0; //绑定数据源 public void GetDate() { if (Request.QueryString["pager"] != null) { string GetDateSql = "SELECT * FROM ( SELECT ROW_NUMBER() over(order by id) as pid,*FROM [Info]) AS aa where aa.pid>=" + Request.QueryString["pager"] + ""; using (SqlConnection conn = new SqlConnection(ConStr)) { conn.Open(); DataSet dt = new DataSet(); SqlDataAdapter sdt = new SqlDataAdapter(GetDateSql, conn); sdt.Fill(dt); this.Repeater1.DataSource = dt; this.Repeater1.DataBind(); } } else
//初次加载不传入任何页码，默认显示前十条 { string GetDateSql = "SELECT * FROM ( SELECT ROW_NUMBER() over(order by id) as pid,*FROM [Info]) AS aa "; using (SqlConnection conn = new SqlConnection(ConStr)) { conn.Open(); DataSet dt = new DataSet(); SqlDataAdapter sdt = new SqlDataAdapter(GetDateSql, conn); sdt.Fill(dt); this.Repeater1.DataSource = dt; this.Repeater1.DataBind(); } } } //得到页码 public void GetPager() { string GetTotal = "SELECT COUNT(*) FROM [Info]"; using (SqlConnection conn = new SqlConnection(ConStr)) { conn.Open(); SqlCommand comm = new SqlCommand(GetTotal,conn); int i = Convert.ToInt32(comm.ExecuteScalar()); int totalPageNum = (i + 10 - 1) / 10;//一共的页数 int j = 0;//记录当前页 string FirstPager = string.Empty;//首页 string LastPager = string.Empty;//尾页 string NextPager = string.Empty;//下一页 string PrePager = string.Empty;//上一页 int next = 0;//记录下一页页码 int pre = 0;//记录上一页页码 for (j = 1; j <= totalPageNum; j++) { //Request.QueryString["value"]接受的是页码值 if (Request.QueryString["value"] == null) { startcount = (1 + 5) > totalPageNum ? totalPageNum - 9 : 1 - 4;//中间页起始序号 //中间页终止序号 endcount = 1 < 5 ? 10 : 1 + 5; if (startcount < 1) { startcount = 1; } //为了避免输出的时候产生负数，设置如果小于1就从序号1开始 if (totalPageNum < endcount) { endcount = totalPageNum; } //页码+5的可能性就会产生最终输出序号大于总页码，那么就要将其控制在页码数之内 } else { startcount = (int.Parse(Request.QueryString["value"]) + 5) > totalPageNum ? totalPageNum - 9 : int.Parse(Request.QueryString["value"]) - 4;//中间页起始序号 //中间页终止序号 endcount = int.Parse(Request.QueryString["value"]) < 5 ? 10 : int.Parse(Request.QueryString["value"]) + 5; if (startcount < 1) { startcount = 1; } //为了避免输出的时候产生负数，设置如果小于1就从序号1开始 if (totalPageNum < endcount) { endcount = totalPageNum; } //页码+5的可能性就会产生最终输出序号大于总页码，那么就要将其控制在页码数之内 } } if (Request.QueryString["value"] == null) { next = 1 + 1; pre = 1; } else { next = int.Parse(Request.QueryString["value"]) + 1; pre = int.Parse(Request.QueryString["value"]) - 1; //判断并进行越界处理 if(pre<=0) { pre = 1; } if(next>totalPageNum) { next = totalPageNum; } } for (j = startcount; j <= endcount; j++) { if (Request.QueryString["value"]==null) { pager += "<a class="hrefName" href="WebForm2.aspx?pager=" + 10 * (1 - 1) + "&value=" + 1 + "">" + j + "</a>|"; } else if (int.Parse(Request.QueryString["value"]) == j) { pager += "<a class="hrefName" href="WebForm2.aspx?pager=" + 10 * (j - 1) + "&value=" + j + ""><span style="color:red">" + j + "</span></a>|"; } else { //10 * (j - 1)这个公式的意思是（当前页码-1）*10，可以跳转到对应页码查看相关的数据 pager += "<a class="hrefName" href="WebForm2.aspx?pager=" + 10 * (j - 1) + "&value=" + j + "">" + j + "</a>|"; } } FirstPager = "<a class="hrefName" href="WebForm2.aspx?pager=" + 10 * (1 - 1) + "&value=" + 1 + ""> 首页</a>|"; LastPager = "<a class="hrefName" href="WebForm2.aspx?pager=" + 10 * (totalPageNum - 1) + "&value=" + totalPageNum + ""> 尾页</a>|"; NextPager = "<a class="hrefName" href="WebForm2.aspx?pager=" + 10 * (next - 1) + "&value=" + next + ""> 下一页</a>|"; PrePager = "<a class="hrefName" href="WebForm2.aspx?pager=" + 10 * (pre - 1) + "&value=" + pre + ""> 上一页</a>|"; RePager = FirstPager + PrePager+ pager + NextPager + LastPager;//拼凑字符串 } } //跳转到第几页的方法 protected void BtnOk_Click(object sender, EventArgs e) { if (Request.QueryString["value"] == null) { Response.Redirect("WebForm2.aspx?pager=" + 10 * (Convert.ToInt32(this.TxtPager.Text) - 1)+"&value=" + this.TxtPager.Text ); } } } }
附带几条公式，如有不对，希望大家指正
信息条数/每页显示条数=一共的页数
开始页码= (当前显示页+ 5) > 总页? 总页 - 9 : 当前显示页 - 4;//中间页起始序号
//中间页终止序号
结束页码= 当前显示页 < 5 ? 10 : 当前显示页+ 5;